Nokia 8810

Firmware version
*#0000# or *#8810#
IMEI Code
* # 06 #
Warranty Codes
*#92702689# (= *#war0anty#)

Just scroll down through the information. If entering the above code requires a
further warranty code try entering the following-

6232 (OK) - Month and year of manufacture
7332 (OK) - Last repair date
7832 (OK) - Purchase date (if previously set)
9268 (OK) - Serial number
37832 (OK) - Set purchase date (this can only be done once)
87267 (OK) - Confirm transfer

Enhanced Full Rate (EFR) and Half Rate Mode (HFR)

*3370# to activate Enhanced Full Rate - Makes calls sound better, but
decreases the battery life by about 5%.(I recommend this one)
#3370# to deactivate Enhanced Full Rate
*4720# to activate Half Rate Mode - Drops call quality, but increases battery
life by about 30%.
#4720# to deactivate Half Rate Mode